1. Field of The Invention
The invention relates to a method of tanning hides and skins and also to a method of retanning hides and skins. More specifically it relates to the use of a certain dicarbamoylsulfonate as a novel tanning and retanning agent for hides and skins.
2. Description of The Art
The bisulfilte adducts of tolylene diisocyanate, n-butyl-isocyanate and hexamethylene diisocyanate are known to be tanning agents for catgut, U.S. Pat. No. 2,923,594, but not for any type of hides and skins. The hexamethylene and tolylene adducts are also known to increase the viscosity of solutions of gelatin, U.S. Pat. No. 3,220,864. Dicarbamoylsulfonates made from tolylene diisocyanate and hexamethylene diisocyanate were tested as tanning agents but it was found that very few crosslinks were introduced, J. Soc. Leather Trades Chem. 49, 455, 1965.